\^▐fres-(_▐)kō\ n [It, fr. fresco fresh, of Gmc origin; akin to OHGr frisc fresh] (1598) Method of painting in which pigments mixed only with water are applied to a freshly laid surface of lime plaster. The painted surface is rendered durable by the pigment absorbing calcium hydroxide from the wet plaster, which is converted into insoluble calcium carbonate as the surface dries. The term is sometimes used incorrectly to denote any form of mural painting.